1. Field of the Invention
The present invention generally relates to wireless telecommunications, and more specifically, relates to a system and method for reducing data collisions in a wireless network.
2. Description of the Related Art
Technology advancement has made mobile telephones or wireless communications devices inexpensive and accordingly ubiquitous. As wireless telecommunication devices are manufactured with greater processing ability and storage, they also become more versatile and incorporate many features including direct radio communication capability between two or a group of individual handsets. This direct radio communication capability is commonly known as the push-to-talk (PTT) or “walkie-talkie” feature that allows a user with one handset to communicate with the device of a predefined set of members of a group without dialing a destination telephone number.
In one version of a PTT system, a wireless telecommunication device, such as a handset, uses two frequencies for communicating with the PTT server, one for outgoing and one for incoming communications. The PTT system requires the person who is speaking to press a PTT button while talking and then release it when done. Any listener in the group can then press their button to respond. In this manner, the system determines which direction the signal travels. In a typical configuration, when a user makes a call to a receiving party or a group of receiving parties using the PTT system, the user's handset first makes a request to a remote server by informing the server it is ready to transmit. The remote PTT server verifies that no other party is using the communication channel and the channel is available then assigns the channel to the user. The user's message is received by the server and the server sends the message for each and every receiving party. After the message is transmitted to every receiving party, the channel is released and ready for use by other parties.
During the process described above, when two users press their PTT buttons simultaneously, there is a chance that their respective user devices will send simultaneously access probes to a single base station. If the access probes are sent through same frequency radio signals and same communication channel, a collision may happen and the base station will not be able to identify the radio signals. The collision problem is accentuated when multiple user devices served by a single base station respond simultaneously to paging messages transmitted by the base station. After receiving the paging message, each user device sends an access probe back to the base station and these access probes may collide with each other. The collision problem is especially a problem in a high bandwidth wireless network, such as a Code Division Multiple Access 2000 (CDMA2000) compatible network.
Therefore, it is desirous to have an apparatus and method that reduce the collision of access probes transmitted in the high bandwidth network, and it is to such apparatus and method the present invention is primarily directed.